For conventional-art air-conditioning apparatuses, a heat exchanger has been recently developed which has a segmented structure such that the heat exchanger includes a plurality of heat exchanger segments. This heat exchanger has a circuit configuration in which each heat exchanger segment is connected to a connecting pipe provided with a solenoid valve. Controlling opening and closing of each solenoid valve controls the flow rate of a refrigerant into the corresponding heat exchanger segment, thus controlling the amount of heat exchanged (hereinafter, referred to as “heat exchange amount”) in the heat exchanger (see, for example, Patent Literature 1).
A heat exchanger has also been recently developed which includes flow rate changing means for changing a refrigerant passage in the heat exchanger so that a cooling or heating capacity is appropriately controlled depending on a variable external load (see, for example, Patent Literature 2).